/* scrambledhalton.c: scrambled halton QMC sample sequence */

#include "scrambledhalton.h"

#define MAXDIM 10

double *ScrambledHalton(unsigned nextn, int dim)
{
  int i, j, a, b, m;
  static int priem[MAXDIM]={2, 3, 5, 7, 11, 13, 17, 19, 23, 29};
  static double sample[MAXDIM];
  double fi, bi, bp;

  for(i=0; i<dim; i++)
  {
    b=priem[i];  /* elke component gebruikt andere basis */
    bi=1.0/b;

    fi=0;
    bp=1;
    m=0;
    for (j=nextn; j>0; j/=b)
    {
      bp=bp*bi;
      a=j%b;  /* a is m-de cijfer uit b-aire voorstelling van nextn */
      a=(a+m)%b; /* permutatie van a, methode van  Warnock */
      fi=fi+a*bp;
      m+=1;
    }
    sample[i]=fi;
  }
  nextn+=1;
  return sample;
}